Jeffrey K. Klotz

Bone Marrow Mesenchymal Stromal Cells to Treat Tissue Damage in Allogeneic Stem Cell Transplant Recipients: Correlation of Biological Markers with Clinical Responses

Bone marrow mesenchymal stromal cells (BMSCs) have been used to treat acute graft‐versus‐host disease (GVHD) and other complications following allogeneic hematopoietic stem cell transplantation (SCT). We conducted a phase I trial using third party, early passage BMSCs for patients with steroid‐refractory GVHD, tissue injury, or marrow failure following SCT to investigate safety and efficacy. To identify mechanisms of BMSC immunomodulation and tissue repair, patients were serially monitored for plasma GVHD biomarkers, cytokines, and lymphocyte phenotype. Ten subjects were infused a fixed dose of 2 × 106 BMSCs/kg intravenously weekly for three doses. There was no treatment‐related toxicity (primary endpoint). Eight subjects were evaluable for response at 4 weeks after the last infusion. Five of the seven patients with steroid‐refractory acute GVHD achieved a complete response, two of two patients with tissue injury (pneumomediastinum/pneumothorax) achieved resolution but there was no response in two subjects with delayed marrow failure. Rapid reductions in inflammatory cytokines were observed. Clinical responses correlated with a fall in biomarkers (Reg 3α, CK18, and Elafin) relevant for the site of GVHD or tissue injury. The GVHD complete responders survived significantly longer and had higher baseline absolute lymphocyte and central memory CD4 and CD8 counts. Cytokine changes also segregated with survival. These results confirm that BMSCs are associated with rapid clinical and biomarker responses in GVHD and tissue injury. However, BMSCs were ineffective in patients with prolonged GVHD with lower lymphocyte counts, which suggest that effective GVHD control by BMSCs requires a relatively intact immune system. Stem Cells 2014;32:1278–1288

Male survivors of allogeneic hematopoietic stem cell transplantation have a long term persisting risk of cardiovascular events

Long-term survivors of allogeneic stem cell transplantation (SCT) have increased risk of cardiovascular disease. We retrospectively studied cardiovascular risk factors (CVRFs) in 109 SCT survivors (62 males, 47 females; median age 34 years) five years or more after bone marrow (15) or T cell-depleted peripheral blood (94) SCT for CML (56), acute leukemia (29), MDS (13), and others (11). One death and two cardiovascular events were reported. At five and ten years after SCT, respectively, 44% and 52% had abnormal lipid profiles; 23% of 5-year survivors met the Adult Treatment Panel III threshold for dyslipidemia treatment, which is substantially higher than the age-matched general population. There were significant increases in prevalence of hypertension (p < 0.001), diabetes (p = 0.018), and body mass index (p = 0.044) after SCT compared with baseline. The Framingham general cardiovascular risk score (FGCRS) in males at five years after SCT projected a doubling (median 10.4% vs. 5.4%) in the 10-year risk of cardiovascular events. Females received HRT after SCT, and none had increased FGCRS. Chronic GVHD and C-reactive protein were not associated with CVRF at any time. All CVRFs stabilized between five and ten years after SCT. Thus, SCT survivors have sustained elevations in CVRFs. Males have a significantly increased risk of cardiovascular events in their second and third decade after SCT.

Repair of Impaired Pulmonary Function Is Possible in Very-Long-Term Allogeneic Stem Cell Transplantation Survivors

Both early- and late-onset noninfectious pulmonary injury are important contributors to the nonrelapse mortality seen after allogeneic stem cell transplantation (allo-SCT), particularly in subjects conditioned with high-dose total body irradiation (TBI). To characterize the kinetics of recovery from pulmonary injury in long-term survivors, we collected data on 138 subjects who survived > 3 years (median survival, 10.2 years) after predominantly TBI-based allo-SCT from their HLA-matched siblings. Baseline pulmonary function tests served as the reference for subsequent measurements at 3, 5, 10, and 15 years for each survivor. The only parameter showing a clinically and statistically significant decline post-transplant was adjusted diffusion capacity of lung for carbon monoxide (DLCO), which reached a nadir at 5 years but surprisingly normalized at the 10-year mark. Multivariable modeling identified chronic graft-versus-host disease (P < .02) and abnormal baseline-adjusted DLCO (P < .03) as the only significant factors associated with the decline in adjusted DLCO at 5 years but excluded smoking, conditioning intensity, baseline C-reactive protein level, TBI dose to the lungs, disease, and demographic variables. In conclusion, pulmonary injury as monitored by the adjusted DLCO continues to deteriorate in the first 5 years after allo-SCT but recovers at 10 years.

Cellular immune profiling after sequential clofarabine and lenalidomide for high risk myelodysplastic syndromes and acute myeloid leukemia

Patients with high risk myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) are commonly older with multiple co-morbidities, rendering them unsuitable for intensive induction chemotherapy or transplantation. We report preliminary cellular immune profiling of four cases receiving sequential clofarabine and lenalidomide for high risk MDS and AML in a phase I study. Our results highlight the potential of immune profiling for monitoring immune-modifying agents in high risk MDS and AML.

Radiation exposure from diagnostic procedures following allogeneic stem cell transplantation – How much is acceptable?

Abstract Background Frequent diagnostic radiology procedures in allogeneic stem cell transplantation (SCT) recipients raise concern about the potential harm from incidental radiation. Objectives To determine the cumulative radiation dose from diagnostic studies in allogeneic SCT and its impact on clinical outcome. Patients and methods This retrospective cohort study was conducted to determine the cumulative radiation dose from diagnostic studies following SCT. Sixty-four consecutive patients with hematological malignancies in a single tertiary care institution underwent total body irradiation (TBI)-based myeloablative conditioning followed by six of six human leukocyte antigen (HLA)-identical sibling allogeneic SCT. The median follow-up was 3 years. The cumulative effective dose in mSv from diagnostic radiological studies in the peri-transplant period from day −30 to day +200 was calculated for each patient and its impact on overall survival and non-relapse mortality was determined. Results The median cumulative radiation exposure from diagnostic radiological procedures was 92 mSv (range 1.2–300), representing about 30× the normal annual background radiation for the population and 10% of the 1200 cGy TBI dose used in conditioning. Sixty-five percent of the cumulative radiation exposure was delivered between day +1 and day 100 and computed tomography scans contributed 88%. In multivariate analysis, diagnostic procedures did not significantly impact clinical outcomes. Conclusions While radiation exposure from diagnostic procedures did not impact clinical outcomes the risk of secondary cancers in long-term survivors is likely to be increased. Our results indicate that patients who are acutely ill for prolonged periods can receive clinically significant radiation doses during their hospital care. Our findings should prompt attempts to limit radiation exposure from diagnostic procedures in post-SCT recipients